Daemonorops fissa Complex in West Malesia

Abstract

Daemonorops fissa complex is highly varied in West Malesia, but information about this complex is limited. The objective of the research was to reveal species diversity of Daemonorops fissa complex in West Malesia based on morphological and anatomical characters. Evaluation of morphological characters was conducted in Herbarium Bogoriense (BO) Cibinong Science Centre LIPI, Bogor (West Java). A total of 355 herbarium specimens were observed in this study representing all species of Daemonorops fissa complex. This study explored Daemonorops fissa complex, including the following: 1) species diversity, (2) distribution, (3) morphological variation, (4) anatomical variation and (5) phenetic relationships. Data obtained then was analized descriptively and phenetically. Species of Daemonorops fissa complex in West Malesia share some unique characters such as erect peduncle (to ± 2 cm), alternate leaves, length of involucrum 1 cm, globose fruits, and ruminate endosperm. This complex species consists of eight species namely, D. angustifolia, D. calicarpa, D. fissa, D. grandis, D. lewisiana, D. melanochaetes, D. monticola, D. stenophylla. Daemonorops binnendijkii, D.palembanica and D. trichroa proposed as new synonymies. Daemonorops binnendijkii and D. trichroa are new synonyms to D. angustifolia, and D. palembanica is a new synonym to D. melanochaetes. All species found in lowland rain forest, especially along stream and other wet places or more open areas, swampy area, ridgetop hill Dipterocarp forest, bamboo forest, and river side on altitude from 250 m – 1900 m asl. Morphological variation of Daemonorops fissa complex in West Malesia could be differentiated into 20 morphological characters. Cluster analysis separated all species into two main groups with coefficient similarity of 36%. Group I consisted of D. angustifolia, D. fissa, D. grandis, D. melanochaetes, D. monticola and D. stenophylla, while group II consisted of D. calicarpa and D. lewisiana. They were separated from five characters, total height, number of leaflets, width of leaflets, type of inflorescence and type of spine in leafsheath. Leaf anatomical characters of paradermal section could not be used to separate among species within D. fissa complex, but leaf anatomical characters of transverse section could be used to identify among species. All examined species of D. fissa complex have three similar characters, tetracytyc stomata, cryptopor type with sunken position and cell wall of sinous, but they have different pattern of bulliform cell and palisade tissues. Both characters are considered as two valuable new characters for supporting morphological data for species delimitation.